Patent GB-991320-A (GB)
Title: Improvements relating to the stabilisation of light and oxidation sensitive organic materials
IPC: D06M13/35
Filed: 1962-06-15
Abstract: 2 - (21Hydroxy - 51 - acylaminophenyl)-benztriazole compounds of the general formula <FORM:0991320/C2/1> wherein R1 represents hydrogen or an alkyl, alkenyl, cycloalkyl or aralkyl radical which may be substituted by a carboxy or carbalkoxy group or R1 and "Acyl," together with the amino nitrogen atom can form a ring when R1 is a carbonyl or unsubstituted or alkyl substituted methylene group, and wherein the nucleus may be substituted in the 4, 5 or 6 positions by alkyl, alkoxy, carboxy, carboxylic acid ester or amide, sulphonic acid amide or alkyl-sulphonyl groups or halogen and at the 31 and 41 positions by alkyl, cycloalkyl, aralkyl or aryl groups or halogen, are incorporated into light and oxidation sensitive organic materials to stabilize said materials. The "Acyl" group is a radical of the formula <FORM:0991320/C2/2> wherein X is a carbon atom or the radical <FORM:0991320/C2/3> and Y is oxygen or an imino group which with X and R2 forms a s-triazine or pyrimidine ring or, when X is carbon, a sulphur atom and R2 is an alkenyl, cycloalkyl, aralkyl or substituted or unsubstituted alkyl or aryl group, or a substituted or unsubstituted amino group, an imino group of a saturated monocyclic heterocycle or, if R1 and R2 are linked together, together with X and R1, it represents the remainder of a lactam or dioxopyrrolidine ring. These compounds may be prepared by heating, in a weakly acid to weakly basic medium and possibly in an inert organic solvent, a 2-(21-hydroxyphenyl) benztriazole compound having an acylatable amino group in the 31 position with an acylating agent.  Other methods of preparation are (1) oxidative ring closure of 2 - amino - 21 - hydroxy - 51 - acylamino -1 ,11-azobenzene with a salt of divalent copper in a neutral to alkaline medium; (2) reductive ring closure of 2-nitro-21-hydroxy-51-acylamino-1,11-azo-benzene e.g. by zinc in alkaline medium; (3) dealkylation of 2-(21-alkoxy-51-acylaminophenyl) benztriazole; (4) saponification of 2-(21-acyloxy-51-acylaminophenyl) benztriazole; and (5) modification of groups in an existing compound of Formula I.  Several examples of the preparation and use of compounds of the invention are given.ALSO:Synthetic polymers, natural polymers or synthetic modifications thereof are stabilized against light and oxidizing agents by incorporating therein a compound of the general formula <FORM:0991320/C3/1> wherein R1 represents hydrogen or an alkyl, alkenyl, cycloalkyl or aralkyl radical which can be substituted by a carboxy or carbalkoxy group or R1 and "Acyl" together with the amino nitrogen atom can form a ring when R1 is a carbonyl or unsubstituted or alkyl-substituted methylene group, and wherein the nucleus may be substituted in the 4, 5 or 6 positions by alkyl, alkoxy, carboxy, carboxylic acid ester or amide, sulphonic acid amine or alkyl-sulphonyl groups or halogen and at the 31 and 41 position by alkyl, cycloalkyl, aralkyl and aryl groups or halogen. The "Acyl" group is a radical of the formula <FORM:0991320/C3/2> wherein X is a carbon atom or the radical <FORM:0991320/C3/3> and Y is oxygen or an imino group which with X and R2 forms an s-triazine or pyrimidine ring or, when X is carbon, a sulphur atom, and R2 is an alkenyl, cycloalkyl, aralkyl or substituted or unsubstituted alkyl or aryl group, or a substituted or unsubstituted amino group, or an imino group of a saturated monocyclic heterocycle or, if R1 and R2 are linked together, together with X and R1, it represents the remainder of a lactam or dioxopyrrolidine ring.  Specified polymers are the addition polymers of vinyl chloride, vinylidene chloride, styrene, butadiene, isoprene, ethylene, propylene, acrylonitrile and methylacrylate and copolymers thereof; polyesters; polyamides; polyester resins; cellulose; cellulose esters and ethers; and proteins.ALSO:Fats, waxes and oil are stabilized against light and oxidizing agents by incorporating therein a compound of the general formula <FORM:0991320/C4-C5/1> wherein R1 represents hydrogen or an alkyl, alkenyl, cycloalkyl or aralkyl radical which can be substituted by a carboxy or carbalkoxy group or R1 and "Acyl" together with the amino nitrogen atom can form a ring when R1 is a carbonyl or unsubstiuted or alkyl-substituted methylene group, and wherein the nucleus may be substituted in the 4, 5 or 6 positions by alkyl, alkoxy, carboxy, carboxylic acid ester or amide, sulphonic acid amide or alkyl-sulphonyl groups or halogen and at the 31 and 41 position by alkyl, cycloalkyl, aralkyl and aryl groups or halogen. The "Acyl" group is a radical of the formula <FORM:0991320/C4-C5/2> wherein X is a carbon atom or the radical <FORM:0991320/C4-C5/3> and Y is oxygen or an imino group which with X and R2 forms an s-triazine or pyrimidine ring or, when X is carbon, a sulphur atom, and R2 is an alkenyl, cycloalkyl, aralkyl or substituted or unsubstituted alkyl or aryl group, or a substituted or unsubstituted amino group, or an imino group of a saturated monocyclic heterocycle or, if R1 and R2 are linked together, together with X and R1, it represents the remainder of a lactam or dioxopyrrolidine ring. Also mentioned are lacquers for coating light-sensitive materials comprising a compound of the general formula I.  In an example the autoxidation of a petroleum distillate oil is retarded by the addition of various compounds of Formula I.  In another example intermediate 2-nitro -21-hydroxy-51-acylaminoazobenzenes are prepared by diazo-coupling of o-nitroaniline with N - acetyl - p - aminophenol or p - N - b -carboxypropionyl - N - butylaminophenol or p - (N - carboxyethyl - N - benzoyl - amino)-phenol.ALSO:Surfaces are coated with polymers that have been stabilized against light and oxidizing agents by incorporating therein a compound of the general formula <FORM:0991320/B1-B2/1> wherein R1 represents hydrogen or an alkyl, alkenyl, cycloalkyl or aralkyl radical which can be substituted by a carboxy or carbalkoxy group or R1 and "Acyl" together with the amino nitrogen atom can form a ring when R1 is a carbonyl or unsubstituted or alkyl-substituted methylene group, and wherein the nucleus may be substituted in the 4, 5 or 6 positions by alkyl, alkoxy, carboxy, carboxylic acid ester or amide, sulphonic acid amide or alkylsulphonyl groups or halogen and at the 31 and 41 position by alkyl, cycloalkyl, aralkyl and aryl groups or halogen.  The "Acyl" group is a radical of the formula <FORM:0991320/B1-B2/2> wherein X is a carbon atom or the radical <FORM:0991320/B1-B2/3> and Y is oxygen or an imino group which with X and R2 forms an s-triazine or pyrimidine ring or, when X is carbon, a sulphur atom, and R2 is an alkenyl, cycloalkyl, aralkyl or substituted or unsubstituted alkyl or aryl group, or a substituted or unsubstituted amino group, or an imino group of a saturated monocyclic heterocycle or, if R1 and R2 are linked together, together with X and R1, it represents the remainder of a lactam or dioxopyrrolidine ring.  In the examples glass is coated with stabilized polyacrylonitrile, and cellulose-acetobutyrate, -acetate and propionate.